Method and device for protecting earth injected materials from contaminants

ABSTRACT

The present invention provides methods and apparatus for soil stabilization. First, a void is formed in the compromised soil strata. Then, an expandable member containing expandable materials is placed into the void. As the material expands to fill the void, the surrounding soil is compressed. This in situ compression if the soil increases the load bearing capacity and compressive strength of the soil. Additionally, the present invention provides a method for isolating the injected materials from the environment at the injection and/or polymerization point.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/172,438, filed Apr. 24, 2009, the entire contents of which arehereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to soil compression. The presentinvention also relates to a method and apparatus for increasing the loadbearing capacity and compressive strength of the soil. Additionally, thepresent invention relates to a method for isolating the injectedmaterials from the environment at the injection and/or polymerizationpoint.

BACKGROUND OF THE INVENTION

The bearing capacity of base soil material is not always sufficient forthe intended structure's design and use. A notable example is the Towerof Pisa. Construction of the first floor of The Tower of Pisa began onAug. 9, 1173. The tower began to sink after construction progressed tothe third floor in 1178. This was due to a mere three-meter foundation,set in weak, unstable subsoil. Construction was subsequently halted foralmost a century. This allowed time for the underlying soil to settle.Unfortunately, to wait a century for the foundation to settle is notacceptable.

Since then, a variety of methods and designs have been used to improvethe bearing capacity of unstable subsoil. Typically, the bearingcapacity is improved by increasing the confined compressive strength ofthe base soil material. Various methods for remedial stabilization ofthe subsoil and/or lifting of the structure to correct structuralsettlement include driving pilings, piers, segmented cylinder piles,and/or micro-piles. Also, other systems that transfer the structuralweight to deeper more solid soils have been used.

Also, conventional stabilization and/or lifting systems include themethod described in U.S. Pat. No. 4,567,708. This patent discloses theinjection of an expandable substance beneath a built structure to fillvoids and the polymerization the substance which results in an expansiveforce that increases in volume to fill voids.

U.S. Pat. No. 6,634,831, which is incorporated by reference herein inits entirety, discloses injecting an expandable substance through holesor tubes into the soil to produce compaction of the contiguous soil.This system fails to account for and/or monitor unknown and unexpectedmigration of the expandable substance away from the injection site. Thismigration is common due to fracturing of the soil at the point ofinjection and the injected materials following the path of leastresistance. Additionally, the uncontrolled migration of the expandablematerial creates undesired surface lifting some distance away from thedesired location.

U.S. Pat. No. 6,521,773, which is incorporated by reference herein inits entirety, discloses polyurethane forming reaction mixtures having awater insoluble diluent. The compositions provided permit the formationof polyurethanes in the presence of excess water. This compositionaddresses the degradation of a typical polyurethane foam compositionwhen excess water is incorporated into the mixture.

The methods and compositions of the prior art have not met the need forcontrolling the unknown and unexpected migration of the injectedmaterial away from the injection point. Additionally, the methods of theprior art have not met the need for isolating the injected material fromenvironmental contaminants.

The present invention provides methods for controlling the placement ofmaterials when injected through a hole or tube, isolating the injectedmaterials to insure that the injected materials are not compromised byenvironmental contaminants, and/or stabilizing unstable subsoil,increasing the load bearing and compressive strength of soil.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a system and method for stabilizingsoil. In general this method comprises the steps of creating a void incompromised soil strata, placing an expandable member in the void, andinjecting the expandable member with an expandable material.

In some embodiments of the present invention, the step of creating avoid is selected from the group consisting of forming a hole, insertinga tube, inserting a pipe, drilling, pressing, and vibration intrusions.In additional embodiments, the expandable member is selected from agroup consisting of a high burst strength bladder, a high temperaturebladder, a rubber bladder, a plastic bladder, and a bladders made of atleast one synthetic material. In specific embodiments, the expandablemember further comprises at least one blow out membrane. In otherembodiments, the step of injecting the expandable material is controlledby a plug.

In additional embodiments of the present invention, a method forstabilizing soil comprises the steps of creating a plurality of voids incompromised soil strata, placing at least one tube in the void, securingan expandable member to a location in the tube, and injecting theexpandable member with an expandable material. In some embodiments, thestep of creating a plurality of void is selected from the groupconsisting of forming a hole, inserting a tube, inserting a pipe,drilling, pressing, vibration intrusions and a combination thereof. Inother embodiments, the expandable member is selected from a groupconsisting of a high burst strength bladder, a high temperature bladder,a rubber bladder, a plastic bladder, a bladders made of at least onesynthetic material and a combination thereof. In specific embodiments.the expandable member further comprises at least one blow out membrane.In yet another embodiment, the step of injecting the expandable materialis controlled by a plug.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter which form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiment disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present invention. It should also be realized by thoseskilled in the art that such equivalent constructions do not depart fromthe spirit and scope of the invention as set forth in the appendedclaims. The novel features which are believed to be characteristic ofthe invention, both as to its organization and method of operation,together with further objects and advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. It is to be expressly understood, however, thateach of the figures is provided for the purpose of illustration anddescription only and is not intended as a definition of the limits ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following descriptions taken in conjunction with theaccompanying drawing, in which:

FIG. 1 shows schematic of how the tubes are placed, the expandablebladder is inserted and the expandable material is injected; and,

FIG. 2 shows an expanding bladder coupled to tubing using a collar and atube crimp.

DETAILED DESCRIPTION OF THE INVENTION

Once it is discovered that the soil underneath a structure is unstable,the methods and apparatus provided by the present disclosure may be usedto stabilize the soil. In general, the method for stabilizing the soilincludes creating a void, placing an expandable member in the void, andinjecting the expandable member with an expandable material.

In some cases, the soil is unstable due to the natural formation of avoid in the subsoil. In other cases, the soil is unstable because thesoil is not settled or compressed enough to support the structure. Inthis situation, a void must be created. The methods for creating a voidinclude, but are not limited to, forming a hole, inserting a tube orpipe, drilling, pressing, or vibration intrusions into compromised soilstrata. Compromized soil strata is characterized by less than desirableconfined soil strength sub-surface locations. For example, a tube may beplaced in the hole. The lower end of the tube is protected to allow thedispensing of material through the tube and the material is allowed toexit at the lower end.

The means for placing the expandable member in the void is accomplishedin a number of ways. In some non-limiting examples, a collar device thatholds the expanding bladder is inserted into a tube and placed at alocation in the tube, 106, where it is desired for the injected materialto expand. In particular examples, this location is the proximate end ofthe tube. The location of the holder, the collar deviced, 102, used toplace the expandable member, 103, is controlled by a stop crimpingelement, 101, placed in the tube prior to inserting the tube into theground.

In some examples, the holder is placed in the tube either by the forceof the injected materials moving the holder through the tube, or byusing an advancer rod, 107, to push the collar and bladder to thedesired location.

In the examples where the collar is placed by the pressure generatedfrom the injected material, the expandable member may be protected by ablow out membrane to prevent the expansion of the capsule during thetravel through the tube. In some cases, the expandable member is abladder. In other cases, the expandable member includes, but is notlimited to high burst strength bladders, high temperature bladders,bladders that have at least one blow out membrane designed for bladderprotection, rubber bladders, plastic bladders, bladders made ofsynthetic materials, and/or bladders made of various combinations ofsynthetic materials.

FIG. 1 shows schematic of how the tubes are placed, the expandablebladder is inserted and the expandable material, 104, is injected.First, a hole is drilled and a tube is put in place. The tube containsan internal crimp, 101. Next, an advancer rod, 107, is used to securethe expandable member, 103, at the end of the tube, 106. Once theexpandable member is secured at the end of the tube, the advancer rod isremoved and the expandable material, 104, is injected resulting in anexpandable member filled with expandable material which is shown as 105in FIG. 1.

In some aspects of the present invention, a stepped metal or plasticcollar is used to attach an expanding bladder at the end of theinjection tube. The injection tube is inserted into a hole and theexpandable material is injected. For example, FIG. 2 shows an expandingbladder, 205 coupled to a ⅝ inch tubing, 201, using a 9/16 inch collar,202, and a 7/16 inch inner diameter tube crimp, 204, with the rim of theexpanding bladder, 203, positioned between 204 and 202. The skilledartisan would readily recognize that larger and smaller diameter tubing,collars and/or tube crimps are within the spirit and scope of thepresent invention.

In some aspects of the present invention, the expandable member is madeof material, which will both expand to a sufficient size and ischemically inert with respect to the injected materials.

Some aspects of the present invention include a means for attaching theexpanding bladder at a given position at the bottom of the injectiontube and/or hole.

In some cases, the present invention provides a means for controllingthe placement of the collar and the attached expandable member near theend of the tube.

In an additional example, a plug is placed on the collar for theexpandable member. This provides a means to control the flow ofexpandable material into the expanding member.

In additional examples, the methods and apparatus used to stabilize thesoil includes placing a collar equipped with an expandable memberdirectly in the void without using tubes and injecting the expandablemember with an expandable material.

In some cases, the expandable material will cause the expandable memberto rupture, leak and/or burst.

Additionally, a network of tubes equipped with expandable members may beused in combination to stabilize the subsoil. In some examples, thenetwork may constructed by placing a collar equipped with an expandablemember directly in the void without using tubes and/or placing tubesequipped with expandable members into the void.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. Moreover, thescope of the present application is not intended to be limited to theparticular embodiments of the process, machine, manufacture, compositionof matter, means, methods and steps described in the specification. Asone of ordinary skill in the art will readily appreciate from thedisclosure of the present invention, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present invention.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps.

1. A method for stabilizing soil comprising: creating a void incompromised soil strata; placing an expandable member in the void; and,injecting the expandable member with an expandable material.
 2. Themethod of claim 1, wherein the step of creating a void is selected fromthe group consisting of forming a hole, inserting a tube, inserting apipe, drilling, pressing, and vibration intrusions.
 3. The method ofclaim 1, wherein the expandable member is selected from a groupconsisting of a high burst strength bladder, a high temperature bladder,a rubber bladder, a plastic bladder, and a bladders made of at least onesynthetic material.
 4. The method of claim 3, wherein the expandablemember further comprises at least one blow out membrane.
 5. The methodof claim 1, wherein the step of injecting the expandable material iscontrolled by a plug.
 6. A method for stabilizing soil comprising:creating a plurality of voids in compromised soil strata; placing atleast one tube in the void; securing an expandable member to a locationin the tube; and, injecting the expandable member with an expandablematerial.
 7. The method of claim 6, wherein the step of creating aplurality of void is selected from the group consisting of forming ahole, inserting a tube, inserting a pipe, drilling, pressing, vibrationintrusions and a combination thereof.
 8. The method of claim 6, whereinthe expandable member is selected from a group consisting of a highburst strength bladder, a high temperature bladder, a rubber bladder, aplastic bladder, a bladders made of at least one synthetic material anda combination thereof.
 9. The method of claim 8, wherein the expandablemember further comprises at least one blow out membrane.
 10. The methodof claim 6, wherein the step of injecting the expandable material iscontrolled by a plug.